The “nano” and “pico” were not two ships sailed by Columbus.
So you have some idea that a 1.2 gigabyte hard drive on your computer is preferable to a 500 megabyte hard drive, but you’re not quite sure why. Or perhaps you’ve heard of curies, but don’t know if picocuries are bigger or smaller, or by how much. This table will help! We give the prefix name, multiple it represents, decimal equivalent, common symbol, and the name in plain old English. To practice using these prefixes, see the worksheet on converting units.
| Multiple | Decimal equivalent | Prefix | Symbol | English |
|---|---|---|---|---|
| 109 |
1,000,000,000 | giga | G | billion |
| 106 |
1,000,000 | mega | M | million |
| 103 |
1,000 | kilo | k | thousand |
| 102 |
100 | hecto | h | hundred |
| 101 |
10 | deca/deka | da | ten |
| 100 |
1 | (none needed) | (n/a) | (n/a) |
| 10-1 |
0.1 | deci | d | tenth |
| 10-2 |
0.01 | centi | c | hundreth |
| 10-3 |
0.001 | milli | m | thousandth |
| 10-6 |
0.000001 | micro | ยต (mu) | millionth |
| 10-9 |
0.000000001 | nano | n | billionth |
| 10-12 | 0.000000000001 | pico | p | trillionth |